Electric-resistance furnace.



PATENTED JUNE 4, 1907.

E. P. PRICE. ELECTRIC RESISTANCE FURNACE.

APPLIOATIQH FILED NOV.14. 1906.

5 5 ed to flexibla-water-supply and dischargemechanism 12. The furnaceody,

UNITED STATES PATENT OFFICE.

EDGAR F. PRICE, OF NIAGARA FALLS, NEW YORK. ELECTRIC-RESISTANCE FURNACE.

' Specification of Letters Patent.

Patented June 4, 1907.

Application filed Hovember 14, 1905. Serial No- 287.344.

new and useful Improvements in Electric Resistance Furnaces of which the following is a specification. I v

The present invention is an electric resistance furnace for smelting refractory ores and producing'ferrdalloys, calcium c'arbid, etc. Thei'urnace has an open bottom beneath which is amovable hearth or receptacle which receives the molten product and is shifted to withdraw its contents from the product remaining in the furnace. A series of receptacles is preferably employed, each serving inturn as the. hearth or crucible of the furnace.-

Referring to the accompanyingdrawings- Figure 1 is an axial section of a suitable resistance furnace; and Fig. 2 is an axial section of the lower. end of a resistance furnace having'a modified hearth..- i

The furnace shown in Fig. 1 is a vertical stack comprising a downwardly-converging, body 1 of arefractory nonconducting material, such as magnesia or siloxicon firebrick, at the upper and lowerends' of which are carbon electroderings'2, 3..' The body and upper electrode are surrounded by iron wateracketsi i, 5, between which is interposed an insulating ring 6. The upper water-jacket 4 is in contact with the electrode 2 and has an electric terminal 7. The lower electrode 3 is en ported in a water-jacketed steel casting-8 aving an electric terminal 9. The casting 8-has lateral extensions 10 and its lower face is flat and smooth. The upper end of the furnace is closed by a conical iron ring 11 and a bell-and-hop er char ingits electrodes and water-jackets, is supported upon illars 13. Beneath the furnace body and c osing its lower open end is a se arate hearth or crucible 14, the upper e e of whlch isflat and makes a tight oint wit the lower face of the casting 8 and its extensions 10. The hearth 14 is supported and arran ed to reciprocate laterally on a hori- Zontalbed-plate 15 or other suitable support. The hearth preferably consists of a rectan ular steel casting, having a refractory lining and containing achamber which is connect pipes 'A duplicate hearth 14 is also supaccumulates in the movable heart ported on the-bed-plate 15. At opposite sides of the furnace are long fluid-pressure cylinders 16,16, the piston rods 17, 17' of which have heads arranged to bear against the outer surfaces of the movable hearths 14, 14'. i

In employing this furnace, a charge which is electrically conductive or which will be converted into a conductor by the temperature of the furnace-for example, a mixture of lime and carbon for' the roduction of calcium carbid-is fed into t e stack until its upper portion lies in contact with the upper ctrode-ring. If the charge is normally a poor conductor, initial current-paths be tween the electrodes are provided. The conductivity of the charge may be increased by using a mixture containing large pieces of coke which lie in contact with each other at various points. An electric current of suilicient amperage is then passed between the electrodes and through the charge, serving as a resistance-conducton The charge is thereby heated, its temperature gradually increasing downward by reason of the de creasing cross-section and increasing currentdensity, to a zone where the materials react to form carbid and the carbid is brought into a molten condition. The carbid adually 14 and when this is nearly filled, the pusher 17 of the cylinder 16 is actuated to move the duplicate hearth 14 beneath and in contact with the lower face of the casting 8 and against'the side of the hearth 14. The continued movement of the pusher then forces the hearth 14 with its charge of carbid gradually out from beneath the bottom of the furnace-chamber and simultaneously moves the duplicate hearth 14 into position to receive another body of carbid. 14 is discharged, as by inverting it, and is then ready to replace the duplicate hearth 14 when the latter is filled, the cylinder 16 and its piston rod 17 being actuated to move the hearth 14 into its orignial osition. Water, liquid ammonia or other cooling medium is circulated through the chambers of the water-jackets, casting 8 and hearths, throughout the rocess, and fresh chargematerials are fed Into the furnace as required.

F1 2 shows the lower end of a'furnacc 'whic is identical in its general construction with that of'Fig. 1, but which has a hearth consisting of anopen trough 18, divided transversely into e number of abutting sec- The hearth A transverse Water-cooled dam or partition 4 close contact with the bottom and sides of IO the furnace, and the molten or an electric current through-the charge, servtions. The sections are arranged to slide on a bed plate 15, with the-fiat upper facesofsides in contact with the lower faces of the. casting 8 and its extensions 10. The sections preferably have cooling chambers and may be lined, like the pan-hearths 14.

i9 depends from the casting 8 and makes the trough-scctions, thereby preventing the molten furnace-product frordfiowing into the incoming section 18". In operation, the row of abutting trough-sections is either con tinuously or intermittently moved along the. bed-plate and beneath the 'open bottom of pasty product flows into and fills the trough, the portion lying Within the dotted lines .20 remaining liquid or plastic while the portion filling the outgoing sections 18 is solid or sufficiently rigid to prevent leakage from the furnace. As each filled section leaves the ihlrnace, its contents'is broken or cut oif from that in the succeeding section and it is then emptied and transferred to the rear of the line of sections.

1. An electric furnace, comprising a smelting chamber having a discharge opening, means for heating said chamber by a resistance conductor, and a receptacle -movable across said discharge opening and arranged to retain a molten body within said chamber, as set forth.

2. An electric furnace, comprising a smelting chamber having a discharge opening, means for heating said chamber by a resistance conductor, and a lurality of recepacles movable across sai discharge opening. and arran ed to retain a molten body within said cham er, as set forth.

3. An electric furnace, com rising a smelting chamber having a disc arge. opening, means for heating said chamber by a resistance conductor, and a plurality of abutting receptacles movable across said discharge opening and arranged to retain a molten body Within said chamber, as set forth.

4. An electric furnace, comprising a smelt ing chamber having a discharge. opening, means for heatingsaid chamber by passing in presence ceases ing as a resistance conductor, and a receptacle movable across said discharge opening and arran ed to retain a molten body Within said chem er, as set forth.

5. An electric furnace, comprising a smelting chamber having a discharge opening, means for heating said chamber by passing an electric current through the charge, serving asa resistance conductor, and a plurality of receptacles movable across said discharge opening and arranged to retain a molten body within said chamber, as set forth.

6. An electric furnace, comprising a smelting. chamber, having a; discharge opening, means for heating said chamber by passing an electric current through the charge, serving as a resistance conductor, and a plurality ,of abutting receptacles movable across said discharge opening and arranged to retain a molten body Within said chamber, as set forth;

.7. An electric furnace, comprising a downwardly-converging stack having an open b0ttom, superposed electrodes in position to con tact with the charge and constitute it a resistance conductor, and a receptacle movable transversely beneath said bottom nd arranged to retain a molten body Within said stack, as set forth.

8. An electric furnace, comprising a downwardly-converging stack having an open bottom,superposed electrodes in position to contact .With the chargeand constitute it a rcsistance conductor, and aplurality of receptacles movable transversely beneath said bottom and arranged to retain a molten body Within said stack, as set forth.

9. An electric furnace, comprising a downwardly-converging stack having an open bottom, superposed electrodes in position to contact with the charge and constitute it a resistance conductor, and a plurality of abutting receptacles movable transversely beneath said bottom and arranged to retain a molten body Within said stack, as set forth.

In testimony whereof, I affix my signature of two Witnesses. fl

, EDGAR F. PRKIE. Witnesses:

G. E. Cox,

D. BURGESS. 

